Process of treating coal-tar and the like



W. ANDERSON.

PROCESS OF TREATING COAL TAR AND THE LIKE.

APPLICATION FILED APR-7,1820.

1,396,003. Patented NOV. 8, 1921.

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W. ANDERSON.

PROCESS OF TREATING COAL TAB AND THE LIKE.

APPLICATION FILED APR. 7. 1920.

Patented Nov. 8, 1921.

3 SHEETS-SHEET 2.

W. ANDERSON.

PROCESS OF TREATING COAL TAR AND THE LIKE.

APPLICATION FILED APR. 7, 1920.

' 1,396,003. Patented Nov. 8, 1921.

3 SHEETS-SHEET 3.

tion.

UNITEDISTATES PATENT OFFICE.-

wxmm ANDERSON, or namnsruaen, scornan'n PROCESS OF TREATING COAL-TAR AND THE LIKE.

- To all whom it may concern:

Be it known that I, WILLIAM ANDERSON, a subject of the King of the United Kingdom of Great Britain and Ireland, and residing at Helensburgh, Dumbartonshire, Scotland, have invented a certain new and useful Process of Treatin Coal-Tar and the like, (for which I have led applications in England on April 3d, 1919, and October 31st, 1919,) of which the following is a specificar This invention relates to a process of treating coal tar.

An important product of the process is a resinous solid, of reddish-brown coloration, of which about 40% is soluble in alkali and about 9% is soluble in acid, the remainder being a solid mixture of hydrocarbons soluble in benzol, ether or vegetable oil, slightly soluble in alcohol or acetone and insoluble in chloroform or acetic acid, the said solid product as a whole being partly soluble in benzol, naphtha, alcohol, acetic acid, etc., and insoluble in water or mineral oil.

While I have not been able to ascertain by analysis the precise composition of the solid product I believe that it contains an oxidized hydrocarbon or hydrocarbons.

The operations comprising the process are :-efi'ecting vaporization of the tar by injecting the tar into and through a tubular heater b means. of superheated steam in excess 0 that required to supply the heat necessary to effect complete vaporization of the tar at the temperature selected, depositing any carbon formed, so as to eifect practically complete separation of carbon, and condensing the vapors.

It is found in practice that satisfactory results are obtained when the temperature of the superheated steam is adjusted so that the supposed interaction takes place between 450 and 600 C.

The vapor and steam are allowed to flow together through a length of tubing sufficient to allow the interaction to develop. In a practical instance 72 feet of tubing have been found sufiicient, the rate of flow being such as to distil 20 tons of tar in 24.- hours.

Though I have no reason to believe that the material of the tube functions as a catalyst I may say that satisfactory results have been obtained with the use of steel tubing.

In order that the solid product hereinbefore referred to may be recovered free 1920. Serial No. 371,890.

from solid carbon, it is desirable next to permit deposition of carbon.

Such deposition is conveniently effected in what may be considered an expansion chamber connected to the tubing, in which chamber adiabatic or isothermal expansion may be effected and the rate of flow retarded, in consequence of which deposition of pure carbon 1s effected in the chamber.

Fromvthe chamber the vapors are passed to a series of condensers so arranged as to effect fractional condensation at any desired series of temperatures. The first of these condensers will collect the solid body while the liquid will be collected in subsequent condensers.

In treating, in the manner above described, coal tar derived from the distillation of coal in Glover-West vertical gas retorts I have obtained the following Liquid product 49% by weight. Solid product "35% Carbon 7% Gas. 9%

The liquid product is similar in appearance to ordinary coal tar creosote.

The solid product i's'as above defined.

No pitch is obtained.

The liquid portion obtained may be treated in the same way as the original material, z. 6., subjected to the action of superheated steam at a temperature between approximately 450 C. and 600 (3., when it is in turn converted into a liquid portion, a solid portion, carbon and gas.

Patented Nov. 8, 1921.

I conclude therefore that chemical condensation is taking place in the tubing concomitantly with oxidation, such chemical condensation taking place to an extent proportionate to the time of reaction in the tubing, the time of reaction being a function of the length of the tubing and the rate of flow..

I have referred to the steam as being present in excess of that required to effect distillation. I have obtained satisfactory results with as much as 25 parts of steam to 100 parts of tar by weight. An apparatus for erformance of the process is illustrated iagrammatically in the accompanying drawings in which Figure 1 is a plan, Fig. 2 a side elevation, and Fig. 3 a front elevation.

1, 1 denote reservoirs from which coal tar, say, is led by valved piping 2 to tubes 3 where the tar is preheated and when; it

asses to the series of tubes 4 into which it is injected, in vaporous form, by superheated steam supplied from the superheafi 5. From the tubes 4 the vapors, etc., pa into the chamber 6. -A steam pipe 7 introduces into the chamber 6. steam flowing in the direction opposed to that of the vapor, etc., entering the chamber 6. From the chamber 6 the vapors pass to'condensers, 8, 9, 10, 11 in which fractional condensation is efiected. 12 denotes a final collecting tank. 13 denotes the gas outlet.

I wish to point out that the present procass is not a hydrogenation process and that I do not produce any oils lighter than those contained as such in the tar or mixture be fore treatment.

In this respect the invention is to be differentiated from hydrogenation processes in which the vapors of tar or of a mixture of coal tar pitch with oil,are reacted on by superheated steam.

I claim:

The process of treating coal tar consisting in effecting vaporization of the tar by injecting the tar into and through a tubular heater by means of steam in excess of that required to supply the heat necessary to effect complete vaporization of the tar while controlling the temperature of the steam, so that the interaction of steam and vapor is effected at a temperature between approximately 450 and 600 0., depositing the carbon formed so as to effect practicall complete. separation of carbon, andcon ensing the vapors to obtain a resinous solid and a liquid product entirely free' from naphthaene.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILLIAM ANDERSON.

Witnesses ISABEL RoLLo, MAY Ross. 

